There is considerable evidence that chronic open angle glaucoma will induce an acquired tritanopic deficit at either the dichromat or anomolous trichromat level in at least some patients. Thhse color defects are seen in tests of color discrimination like the Farnsworth 100 Hue. In addition, scotoma assessed using narrow-band blue targets on a yellow background (the two-color perimetric metod) tend to be larger and more readily detected than scotoma assessed conventionally. These findings have not been exploited in the diagnostic setting. Part of the reason is technological; in order to employ the two-color technique, the target has to be illuminated by a narrow-band spectral source. However, the cost of providing such illumination has decreased so that this is no longer a major problem. A second reason that these findings have not been exploited is that most of the supporting data is derived from case history material. Consequently, we do not know how much of an improvement, if any, these techniques offer compared to conventional methods, in terms of increased hit rates and decreased false alarm rates. The purpose of the proposed research is to evaluate the role of color discrimination and two-color perimetry in the diagnosis and management of chronic open angle glaucoma.